We recently reviewed the article published by Lark et al. (2022) in PNAS, detected various problematic assumptions, approaches, data, and results in that study. Based on our findings, we concluded that these authors overestimated GHG emissions of corn ethanol consumption due to the RFS. In response to our comments, Lark et al. have stated that they believe “Taheripour et al.’s conclusions to be unsupported and based upon several misunderstandings and misinterpretations of [our] methods and results.” In what follows, we review the responses provided by Lark et al. and show that our comments did not misinterpret Lark et al.’s findings, rather that our comments are supported by the literature and actual observation and are based on the statements provided by Lark et al. in their original publication.
In this document, we provide responses to the Lark et al. comments one by one. To avoid confusion, throughout we refer to Lark et al.’s 2022 original publication as Lark et al.(a) and the response of those authors to our original comments as Lark et al.(b).
Our detailed review of the original paper and the responses by those authors reveals various major deficiencies, problematic assessments, and misinterpretation of the existing literature in Lark et al.(a)&(b). In summary, our major findings are: